The Guilty Knowledge Test and the modified Stroop task in detection of deception: an exploratory study

The current study tested whether a simple Stroop paradigm can be used to detect deceptive behavior. 40 university students (34 women), half of whom committed a mock crime, were administered a Guilty Knowledge Test and modified Stroop task to detect guilt or innocence. The Guilty Knowledge Test is a well-known psychophysiological detection method, which consists of multiple-choice questions about details of the crime while skin conductance is recorded. Subjects possessing guilty knowledge are expected to show enhanced differential responses to the relevant stimuli. The modified Stroop task required color-naming of colored words related to the mock crime or an irrelevant crime. Each version of the Stroop task was presented in story form. Subjects possessing guilty knowledge were expected to produce larger reaction times to the relevant version relative to the irrelevant version. The test correctly identified 100% of innocent participants and 78% of guilty participants. In contrast, Stroop interference. i.e., reaction times for irrelevant crime details subtracted from those for mock crime details, did not differentiate between the two groups, suggesting that the story form of the Stroop paradigm is not suitable for lie detection.     

GKT范式在确定犯罪嫌疑人中的应用：一项ERP测谎研究

刑事犯罪已成为当今各国面临的普遍性社会问题,因此急需可靠有效的测谎技术以适应当前打击犯罪的严峻形势。本研究采用犯罪知识测试范式（Guilty knowledge test, GKT）,以犯罪嫌疑人为对象,以真实犯罪现场为素材,探究真实环境下与测谎探测相关的脑电指标（P300、CNV）的有效性和可靠性。行为数据显示,目标刺激的反应正确率显著小于探测和无关刺激,探测刺激的反应时显著小于目标刺激和无关刺激。脑电数据显示,相较于目标刺激和无关刺激,探测刺激诱发的P300波幅最大且P300的检出率为92.5%,而在CNV指标上目标刺激诱发的波幅最大, 无关刺激次之,探测刺激最小。结果表明,与CNV相比,P300能够有效检测被试所隐藏的犯罪细节信息,且检出率较高,稳定性较好,是一种较为可靠的测谎指标。     

Critical elements of the crisis intervention team model of jail diversion: An expert survey

The Crisis Intervention Team (CIT) model of jail diversion is a promising approach to addressing the over-involvement of people with mental illness with the criminal justice system. Despite its popularity and promising empirical support, the literature has yet to clarify CIT's critical elements. The aim of this study was to assess the degree to which experts agreement on the importance and perceived implementation of the critical elements of CIT. Study 1 used a literature review to cull potential elements. Three experts familiar with the CIT model reviewed these elements. Study 2 utilized an online survey of 55 CIT co-ordinators/officers and published experts to assess agreement regarding importance and degree the element is implemented. A preliminary list of 36 elements was identified with a high level of expert agreement on their importance regarding importance and implementation. This study developed a preliminary list of elements of the CIT's program. Further research should develop consensus, explore elements' association with outcomes, and differentiate elements from those common to all jail diversion programs. Copyright © 2010 John Wiley & Sons, Ltd.     

CCTV Observation: The Effects of Event Type and Instructions on Fixation Behaviour in an Applied Change Blindness Task

Little is known about how observers' scanning strategies affect performance when monitoring events in closed‐circuit television (CCTV) footage. We examined the fixation behaviour of change detectors and non‐detectors monitoring dynamic scenes. One hundred forty‐seven participants observed mock CCTV videos featuring either a mock crime or no crime. Participants were instructed to look for a crime, to look for something unusual or simply to watch the video. In both videos, two of the people depicted switched locations. Eye movements (the number of fixations on the targets and the average length of each fixation on targets) were recorded prior to and during the critical change period. Change detection (24% overall) was unaffected by event type or task instruction. Fixation behaviour differed significantly between the criminal and non‐criminal event conditions. There was no effect of instructions on fixation behaviour. Change detectors fixated for longer on the target directly before the change than did non‐detectors. Although fixation behaviour before change predicted change detection, fixation count and durations during the critical change period did not. These results highlight the potential value of studying fixation behaviour for understanding change blindness during complex, cognitively demanding tasks (e.g. CCTV surveillance). Copyright © 2017 John Wiley & Sons, Ltd.     

What are you hiding? Initial validation of the reaction time-based searching concealed information test

The reaction time-based concealed information test (RT-CIT) has been used to judge the veracity of an examinees claim to be naïve by using RTs to test for recognition of relevant details. Here, we explore the validity of the RT-CIT to generate new knowledge about the incident—the searching CIT. In a mock terrorism study (n = 60) the RT-CIT not only allowed to link suspects to known crime details, but also allowed to reveal new crime details well above chance. A simulation study confirms the potential of the searching RT-CIT and identifies conditions under which it performs best. We used an archival dataset that met these conditions (high CIT effect, large number of item repetitions), and found better item classification performance than in the mock terrorism study. The searching RT-CIT could be a new, promising investigative tool to reveal new (e.g., crime) details to the investigative party.     

The Protestant Work Ethic,Expectancy Violations,and Criminal Sentencing1

To test the hypothesis that endorsement of the Protestant work ethic would be related positively to sensitivity to criminal behavior that violated expectations, American college students (N = 159) read scenarios describing a crime committed by a typical or an atypical offender. After answering questions about the crime, they completed Mirels and Garrett's (1971) Protestant Work Ethic (PWE) scale. Extent of punishment was positively related to PWE for atypical criminal behavior. Yet, high PWEs also were more likely to perceive an affluent criminal as experiencing greater remorse for a blue‐collar crime than a white‐collar crime. We relate our results to perceptions of criminal behavior, information‐processing tendencies among individuals endorsing the PWE, and jury selection considerations.     

Intoxicated eyewitnesses: The effect of a fully balanced placebo design on event memory and metacognitive control

Few studies have examined the impact of alcohol on metacognition for witnessed events. We used a 2 × 2 balanced placebo design, where mock witnesses expected and drank alcohol, did not expect but drank alcohol, did not expect nor drank alcohol, or expected but did not drink alcohol. Participants watched a mock crime in a bar‐lab, followed by free recall and a cued‐recall test with or without the option to reply “don't know” (DK). Intoxicated mock witnesses' free recall was less complete but not less accurate. During cued‐recall, alcohol led to lower accuracy, and reverse placebo participants gave more erroneous and fewer correct responses. Permitting and clarifying DK responses was associated with fewer errors and more correct responses for sober individuals; and intoxicated witnesses were less likely to opt out of erroneous responding to unanswerable questions. Our findings highlight the practical and theoretical importance of examining pharmacological effects of alcohol and expectancies in real‐life settings.     

Algorithms for detecting concealed knowledge among groups when the critical information is unavailable

We examined whether the Concealed Information Test (CIT) may be used when the critical details are unavailable to investigators (the Searching CIT [SCIT]). This use may have important applications in criminal investigations (e.g., finding the location of a murder weapon) and in security-related threats (e.g., detecting individuals and groups suspected in planning a terror attack). Two classes of algorithms designed to detect the critical items and classify individuals in the SCIT were examined. The 1st class was based on averaging responses across subjects to identify critical items and on averaging responses across the identified critical items to identify knowledgeable subjects. The 2nd class used clustering methods based on the correlations between the response profiles of all subject pairs. We applied a principal component analysis to decompose the correlation matrix into its principal components and defined the detection score as the coefficient of each subject on the component that explained the largest portion of the variance. Reanalysis of 3 data sets from previous CIT studies demonstrated that in most cases the efficiency of differentiation between knowledgeable and unknowledgeable subjects in the SCIT (indexed by the area under the receiver operating characteristic curve) approached that of the standard CIT for both algorithms. We also examined the robustness of our results to variations in the number of knowledgeable and unknowledgeable subjects in the sample. This analysis demonstrated that the performance of our algorithms is relatively robust to changes in the number of individuals examined in each group, provided that at least 2 (but desirably 5 or more) knowledgeable examinees are included. (PsycINFO Database Record (c) 2012 APA, all rights reserved).     

Eyewitness memory: Balancing the accuracy,precision and quantity of information through metacognitive monitoring and control

Although memory deteriorates over time, people may be able to maintain high accuracy by metacognitively monitoring the quality of their memories and strategically controlling their memory reports. We test two mechanisms of metacognitive control: Exercising a report option (withholding uncertain responses) and adjusting response precision (providing imprecise, but likely accurate, responses). Participants observed a mock crime and were interviewed after 10 minutes or 1 week. Interviews consisted of answerable questions in one of three formats (free narrative, cued recall, yes/no), allowing participants to exert more or less control over their answers. Participants' reports showed tradeoffs between accuracy, quantity and precision of information. Depending on the question format, participants maintained high accuracy even at the delayed report either by opting not to answer (yes/no or cued recall) or by providing imprecise answers (cued recall or free narrative). We discuss implications for experimental research, metacognitive theory and the criminal justice system. Copyright © 2010 John Wiley & Sons, Ltd.     

How schemas affect eyewitness memory over repeated retrieval attempts

After observing a crime eyewitnesses are typically interviewed many times over an extended period of time. We examined how schema for a crime influenced the types of information eyewitnesses remembered and forgot across multiple interviews. People's schema for a bank robbery were identified, and recall of schema‐consistent, schema‐inconsistent and schema‐irrelevant information was extracted from eyewitness interviews conducted in two experiments which manipulated retention interval (3 days–12 weeks) and number of interviews (2–4). Consistent with fuzzy‐trace and associative network theories, schemas preserved accuracy for information central to the crime (schema‐consistent and inconsistent) at the expense of schema‐irrelevant information. Schema‐consistent intrusions did not increase across interviews. Copyright © 2003 John Wiley & Sons, Ltd.     

Effects of socialization on the physiological detection of deception

Effects of socialization on the physiological detection of deception using the control question test (CQT) were explored in three mock crime experiments. Subjects were 168 volunteers from criminal, community, and college student populations. Socialization was measured by the Socialization (So) scale of the California Psychological Inventory. All subjects were given a CQT using standard field techniques. The physiological data were blindly evaluated by a semiobjective field scoring technique and previously developed discriminant function. There were no effects of socialization on the accuracy of classification by the semiobjective field scoring or the discriminant function. A modest negative relationship was found between socialization scores and differential reactivity in the CQT as indicated by correlations with the semiobjective (r = −.22) and discriminant scores (r = −.17). It was concluded that socialization is not an important variable for field applications of the CQT.     

Understanding the weapon focus effect: The role of threat,unusualness, exposure duration,and scene complexity

We examined the role of exposure duration and scene complexity on the weapon focus effect (WFE). Memory for the mock crime was affected more by a weapon than an unusual but nonthreatening object. Threat reduced correct identifications when the event was short but not long; duration of the event did not interact with unusualness. Additionally, we found a WFE for target‐absent lineup decisions, but only for the accomplice lineup, not the object‐wielding perpetrator's lineup. We discuss the implications of these results for illuminating the mechanisms that elicit the WFE.     

Establishing the Duration of Crimes: An Individual Differences and Eye‐Tracking Investigation into Time Estimation

The time available for viewing a perpetrator at a crime scene predicts successful person recognition in subsequent identity line‐ups. This time is usually unknown and must be derived from eyewitnesses' duration estimates. This study therefore compared the estimates that different individuals provide for crimes. We then attempted to determine the accuracy of these durations by measuring observers' general time estimation ability with a set of estimator videos. Observers differed greatly in their ability to estimate time, but individual duration estimates correlated strongly for crime and estimator materials. This indicates that it might be possible to infer unknown durations of events, such as criminal incidents, from a person's ability to estimate known durations. We also measured observers' eye movements to a perpetrator during crimes. Only fixations on a perpetrator's face related to eyewitness accuracy, but these fixations did not correlate with exposure estimates for this person. The implications of these findings are discussed. Copyright © 2013 John Wiley & Sons, Ltd.     

Examining the Role of Similarity Coefficients and the Value of Behavioural Themes in Attempts to Link Serial Arson Offences

When relying on crime scene behaviours to link serial crimes, linking accuracy may be influenced by the measure used to assess across‐crime similarity and the types of behaviours included in the analysis. To examine these issues, the present study compared the level of linking accuracy achieved by using the simple matching index (S) to that of the commonly used Jaccard's coefficient (J) across themes of arson behaviour. The data consisted of 42 crime scene behaviours, separated into three behavioural themes, which were exhibited by 37 offenders across 114 solved arsons. The results of logistic regression and receiver operating characteristic analysis indicate that, with the exception of one theme where S was more effective than J at discriminating between linked and unlinked crimes, no significant differences emerged between the two similarity measures. In addition, our results suggest that thematically unrelated behaviours can be used to link crimes with the same degree of accuracy as thematically related behaviours, potentially calling into the question the importance of theme‐based approaches to behavioural linkage analysis. Copyright © 2012 John Wiley & Sons, Ltd.     

Can implicit measures detect source information in crime-related amnesia?

Participants who are asked to simulate amnesia for a mock crime have a weaker memory for this event when they have to give up their role as a feigner, than those who are not asked to feign memory loss. According to the source monitoring framework (SMF), this memory-undermining effect of simulating amnesia for a crime would be due to misattribution of the right source of information. However, we know that the content of self-generated information (e.g., feigned version of the crime) might be preserved and recognised over time as a result of elaborative cognitive processing. In the present study, we aimed to contrast these two explanations. We showed participants a mock crime video and we instructed them to either feign amnesia (simulators) or confess the mock crime (confessors). Next, a free recall memory test was administered. After one week, participants were asked to perform a personalised source monitoring task using the autobiographical Implicit Association Test (aIAT). As predicted, we found that simulators were able to discriminate the content of their self-generated feigned story of the crime from the original version. Moreover, simulators were quicker than confessors at the aIAT task. Practical and theoretical implications of our results are discussed.     

Extraversion and the detection of deception

Extraversion, neuroticism and threat of punishment were investigated in a detection of deception paradigm. Half of the 96 subjects, by instruction, had committed a mock crime while the other half were innocent of such an act. Extraversion was related to accuracy of detection such that those with high scores on this dimension were more likely to be classified correctly as guilty or innocent. This result had been predicted on the basis that detection is not determined by overall physiological responsiveness to questions but by contrasting responsiveness to critical and non-critical questions. Thus those high on extraversion, who were conceived of as difficult to arouse, responded only to the critical questions in the test while the more arousable introverts masked contrast by responding indiscriminately to both critical and non-critical questions. Neither of the other variables, neuroticism and threat of punishment, were related to detection.     

The Effects of Physical Attractiveness,Race, Socioeconomic Status,and Gender of Defendants and Victims on Judgments of Mock Jurors: A Meta-Analysis1

A meta-analysis of experimental research on mock juror judgments was conducted to assess the effects of physical attractiveness, race, socioeconomic status (SES), and gender of both defendants and victims to test the theory that jurors use characteristics that are correlated with criminal behavior as cues to infer guilt and to recommend punishment. In general, it was advantageous for defendants to be physically attractive, female, and of high SES, although these advantages were nil for some crimes. There were no overall effects of race on mock jurors' judgments, but the effect of defendant race on punishment was strongly moderated by type of crime. Effects of victim characteristics on jurors' judgments were generally inconsequential, although defendants were at a disadvantage when the victim was female.